Equine Osteoarthritis: The Economic Impact

Osteoarthritis (OA) is a painful, debilitating joint disease with no known cure. It is characterized by heat, pain, swelling, crepitus (a crackling, crinkly, or grating feeling or sound under the skin), and a decreased range of motion in affected joints. This condition can develop suddenly (e.g., secondary to a traumatic injury to the joint), or it can develop slowly over the course of months to years.

Recent estimates indicate that 60% of lameness problems in horses are related to OA. Since the U.S. horse population is currently estimated to be 7.3 million (based on a 2007 pet ownership and demographics study published by the American Veterinary Medical Association), this means that over 4 million horses are currently affected by OA!

Not only does OA negatively impact the horse itself, it also affects the 4.6 million people (owners, service providers, and businesses) associated with the equine industry. For example, the American Horse Council reports that the horse industry produces goods and services of $38.3 billion and has a total impact of more than $100 billion on the U.S. gross domestic product. Thus, it is clear that loss of horses due to OA has the potential to cause substantial economic losses.

"It is widely acknowledged that OA is a notable burden on the equine industry, and horse owners are encouraged to consider the economic impact of treating horses with OA," explains David Frisbie, DVM, PhD, Dipl. ACVS, a leading researcher in the field of OA at Colorado State University's Gail Holmes Equine Orthopaedic Research Center.

This article provides a brief look at the potential costs associated with OA, including direct out-of-pocket dollars and estimated costs, such as those associated with loss of function. Owners and trainers likely will be surprised to learn exactly what their horse's joint health costs.

Costs Associated with OA

Studies evaluating the economic burden of human OA typically break costs into "direct" and "indirect" components. Peter Coyte, PhD, of the University of Toronto in Canada, and colleagues described direct costs in a 2005 study in humans. Direct costs are dollars spent on health care, including those covered by the health care system or direct out-of-pocket expenditures by patients for items such as medications, assistive devices, transport, home adaptations, and specialist care fees. In contrast, indirect costs include those associated with lost income, lost leisure time, and costs associated with informal care (e.g., help with personal care and chores provided by unpaid caregivers).

"Our study (in humans) found the average annual cost per patient with OA was $12,200 (Canadian dollars, or approximately $10,000 U.S. dollars)," relays Coyte. "Only one-fifth of these costs were due to direct costs. Instead, the majority of costs associated with OA were indirect, including time lost from employment and leisure and unpaid informal caregiver support."

Not surprisingly, Coyte and co-authors also found that overall costs increased with greater OA severity.

Breaking it Down for Horses

Direct costs of equine OA Most of the direct costs incurred by horses with OA are related to diagnostic and treatment fees charged by veterinarians. Examples of common veterinary service charges for diagnosing and treating OA are summarized in the table below.

Common Osteoarthritis-Related Costs

Direct Medical Expenditure

Estimated Price (USD)

Farm Call fee

$50

Lameness examination

$75-$500 (depending on extent of examination, blocking, etc).

Radiographs (per joint)

$120-$200

If indicated, surgery to remove underlying pathology (e.g., chip fracture of the knee or ankle, single joint)

"The total of these overall direct costs, of course, will vary from case to case depending on severity, financial ability/commitment of the owner, and use of horse, among other factors," says Frisbie.

For example, an athletic horse that develops a chip fracture in a knee or ankle will require surgery to have it removed, lose time from training and performance, need increased care postoperatively, and is anticipated to ultimately develop some degree of OA that will likely require treatment. The horse in this scenario could incur costs to the tune of $3,000-$5,000.

According to Frisbie, "The financial commitment by the owner for a horse that develops OA during the course of its lifetime is likely to be substantial."

On the contrary, an older, nonathletic companion horse with OA can be maintained comfortably with a markedly lower price tag.

Indirect costs of equine OACoyte explains, "Compared to human medicine, estimating the dollar value of indirect costs for equine OA is likely more complex and challenging.

"If one were to assume that indirect costs associated with equine OA were similar in magnitude to human OA, then only 20% of the costs are due to direct medical expenditures," suggests Coyte. "This means that if a horse owner spends $10,000 per year on direct costs, then indirect costs could be as high as $50,000 for a total of $60,000 per horse per year."

Frisbie agrees that while indirect costs are rarely considered in veterinary medicine, the estimates of indirect costs associated with equine OA projected from human research are likely substantially higher than they are in reality.

Instead, Frisbie suggests that one of the major factors that drives the cost of joint care up is the fact that what we as an industry expect out of our horses today is a lot more than what we did even a decade ago.

"It used to be that a Grade 2 or 3 lame horse was acceptable," says Frisbie. "Now, the bar is placed quite a bit higher and horses are expected to compete closer to their peak, which necessitates advanced joint care."

In addition, owners seem to have a higher level of awareness regarding the prevalence and impact of OA in horses and appear to be more willing to treat horses for OA now compared to even a decade ago.

Focus on Prevention

Given the fact that OA is known to be an incurable and invariably progressive condition, research focusing on ways to prevent the initiation or progression of OA in horses is critical; and this research is ongoing. For example, during the 2008 American Association of Equine Practitioners (AAEP) annual convention, C. Wayne McIlwraith, BVSc, PhD, FRCVS, DSc, Dr. med vet (hc), Dipl. ACVS, Barbara Cox Anthony University Chair and Director of Orthopaedic Research at Colorado State University, presented information relating to the prophylactic use of oral joint health supplements (OJHS) in young, healthy horses prior to the onset of any signs of OA.

McIlwraith explained that no studies supporting the use of oral joint health supplements prophylactically in horses have been published, but research has been performed in dogs using a glucosamine/chondroitin sulfate combination product. The scientists found that dogs receiving the oral joint health supplements for 21 days prior to induction of an experimental acute synovitis (inflammation of the joint) had significantly less evidence of joint inflammation compared to the control group or dogs that were treated after the induction of the synovitis.

Despite the lack of equine research in this area, many owners and trainers preventatively use oral joint health supplements. Researchers have demonstrated safety of chondroitin sulfate, avocado- soybean unsaponifiables (ASU), and glucosamine-containing oral joint health supplements in horses, so these products are not likely to be deleterious. However, from an economic standpoint, overusing these products might not be wise.

Potential Treatment-Related Complications

Despite the administrator's best intentions, some medical treatments are not without risk. Complications associated with osteoarthritis (OA)-related therapies can occur, although they are typically quite rare (e.g., <1% of horses are anticipated to develop either an infection or flare following a joint injection). Direct medical costs associated with OA could be markedly increased should any post-treatment adverse events occur. Two key examples are post-injection flares or infections and serious side effects associated with the administration of phenylbutazone (Bute). In terms of joint injections, a joint flare or infection, while relatively rare, requires aggressive therapy. This is essential for the horse's survival and treatment costs can be steep.

"Treatment costs can be quite high if a horse develops a joint infection secondary to intra-articular medication, but fortunately these conditions are typically manageable," says David Frisbie, DVM, PhD, Dipl. ACVS, a leading researcher in the field of OA at Colorado State University's Gail Holmes Equine Orthopaedic Research Center.

A potentially fatal diarrhea secondary to ulceration of the dorsal colon.

--Stacy Oke, DVM, MSc

Carey Williams, PhD, is an equine extension specialist and assistant director of extension at the Equine Science Center at Rutgers, The State University of New Jersey. "One easy way to help control costs associated with the management of OA is to carefully review the supplements being offered to your horses," she advises.

Williams and colleague Amy Burk, PhD, of the University of Maryland, conducted a survey of leading three-day event riders during the 2006 and 2007 Jersey Fresh Three-Day Events. Williams and Burk discovered that these horses were fed an average of four different nutritional supplements per day, including oral joint health supplements.

"Our study revealed that owners and trainers could be oversupplementing their horses," says Williams. "This finding raises concerns not only regarding nutrient balance and potential toxicities, but also regarding the costs associated with unnecessary supplementation. Owners are encouraged to use supplements wisely and discuss their feeding management practices with a nutritionist or veterinarian."

One additional economic concern pertaining to the use of oral joint health supplements relates to the preponderance of poor-quality oral joint health supplements that do not contain the type or amount of ingredient as listed on the manufacturers' labels. As presented by McIlwraith at the 2006 AAEP conference (on behalf of a group of Canadian researchers led by Scott Weese, DVM, DVSc, Dipl. ACVIM, an associate professor in the Department of Pathobiology at the Ontario Veterinary College in Canada), poor-quality equine oral joint health supplements abound. McIlwraith relayed that of 23 oral joint health supplements evaluated, only 14 products contained the amount of glucosamine listed on the manufacturer's product label. That means nearly 40% of the studied products did not contain the expected amount of glucosamine, including one product that did not contain any glucosamine at all.

Poor-quality products provide very low doses of glucosamine that are unlikely to be effective, might contain fillers or other ingredients that are potentially detrimental to the horse (e.g., toxins such as heavy metals or pesticides), and are an unnecessary expense for the owner, advised McIlwraith.

The best way to get the most "bang for your buck," in terms of supplementation, is to carefully select only quality supplements that are most likely to be therapeutically beneficial to your horse(s).

The "ACCLAIM" system is a seven-step process that helps consumers evaluate oral joint health supplement product labels with the goal of identifying quality products that are more likely to benefit the horse.

The ACCLAIM system, described by McIlwraith at the 2008 AAEP conference, addresses such issues as manufacturer information and quality assurance/quality control practices, dosing calculations and instructions, validity of label claims versus testimonials, and consumer support. (For more on the ACCLAIM system, see the article "Oral Joint Supplements".)

Take-Home Message

"A horse's joints are invaluable," says Frisbie. "Since 60% of horses have OA, owners should anticipate that some degree of OA will ultimately develop during their horses' lifetimes. Owners need also be aware that OA can be an expensive disease, but a manageable one."

As described in this story, these direct and indirect costs can be substantial, depending on the degree of OA and the level of care afforded by the horse's caretakers. Not only are there financial costs associated with OA, an immeasurable emotional burden for those caring for affected horses also can result.

"Like everything, however, all of these speculated costs need to be considered relative to other equine-related expenses," advises Frisbie. For example, the cost of boarding a horse alone (at an estimated $350/month) is $4,200 per year.

"Most owners are unlikely to spend anywhere near this dollar amount on their horse's joints in a lifetime," adds Frisbie, "and we haven't even begun to consider the amount of money people spend on the extras, such as treats, routine vaccinations, deworming, and equine-related paraphernalia.

"It all needs to be kept in perspective," he concludes.

About the Author

Stacey Oke, MSc, DVM, is a practicing veterinarian and freelance medical writer and editor. She is interested in both large and small animals, as well as complementary and alternative medicine. Since 2005, she's worked as a research consultant for nutritional supplement companies, assisted physicians and veterinarians in publishing research articles and textbooks, and written for a number of educational magazines and websites.

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